[Prevalence of hemoglobin S in the State of Paraná, Brazil, based on neonatal screening]

Area of Science:

• Medical Genetics
• Public Health
• Hematology

Background:

• Brazil's National Neonatal Screening Program mandates screening for hemoglobinopathies.
• Neonatal screening in Paraná is managed by the Ecumenical Foundation for the Protection of the Handicapped.
• This study aimed to determine prevalence rates of sickle-cell disease and Sbeta-thalassemia in Paraná.

Purpose of the Study:

• To establish the prevalence of sickle-cell anemia and Sbeta-thalassemia in newborns in Paraná.
• To compare HbS prevalence in Paraná with other Brazilian regions.
• To explore potential factors influencing observed prevalence rates.

Main Methods:

• Neonatal screening of blood samples on filter paper using isoelectric focusing (IEF) and high-performance liquid chromatography (HPLC).
• Screening of 548,810 newborns between January 2002 and December 2004.
• Confirmatory testing at six months of age for definitive diagnosis.

Main Results:

• Identified 12 cases of sickle-cell anemia (2.2:100,000 newborns) and 15 cases of Sbeta-thalassemia (2.7:100,000 newborns).
• Diagnosed 8,321 newborns with heterozygous HbS (1,500:100,000 newborns).
• Observed lower HbS prevalence in Paraná compared to other Brazilian regions.

Conclusions:

• The prevalence of sickle-cell anemia and Sbeta-thalassemia in Paraná is lower than in other parts of Brazil.
• Ethnic background and demographic factors may contribute to the lower prevalence of homozygous hemoglobinopathies.
• Sbeta-thalassemia interactions suggest Euro-Mediterranean ancestry within the Paraná population.